<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <link rel="stylesheet" href="../css/reset.css">
    <style>
        .w {
            width: 990px;
            margin: auto;
        }

        .banner {
            height: 460px;
            background-color: #ddd;
        }

        .banner ul {
            width: 200px;
            height: 460px;
            background-color: #eee;
            float: left;

            position: relative;

        }

        .banner li {
            padding-left: 20px;
            line-height: 30px;
            font-size: 14px;

        }

        .banner li:hover {
            background-color: #ff0;
        }

        .banner li a:hover {
            color: red;
        }

        .tu {
            width: 600px;
            height: 460px;
            float: left;
            background-color: #999;
        }

        .hide {
            width: 600px;
            height: 460px;
            background-color: pink;

            position: absolute;
            top: 0;
            left: 200px;

            display: none;
        }

        .banner ul li:hover .hide {
            display: block;
        }
    </style>
</head>

<body>

    <!-- 参照物是ul  不是li -->
    <div class="banner">
        <div class="w">
            <ul>
                <li>
                    <a href="">家用电器</a>
                    <div class="hide">1</div>
                </li>
                <li>
                    <a href="">手机数码</a>
                    <span>/</span>
                    <a href="">运营商</a>
                    <div class="hide">2</div>
                </li>
                <li>
                    <a href="">家用电器</a>
                    <div class="hide">3</div>
                </li>
                <li>
                    <a href="">手机数码</a>
                    <span>/</span>
                    <a href="">运营商</a>
                    <div class="hide">4</div>
                </li>
                <li>
                    <a href="">家用电器</a>
                </li>
                <li>
                    <a href="">手机数码</a>
                    <span>/</span>
                    <span>运营商</span>
                </li>

            </ul>
            <div class="tu"></div>
        </div>
    </div>
</body>

</html>